The specific goal of this project was designed because of a troublesome problem in epilepsy. There is a hard core of patients with partial epilepsy whose seizures are uncontrollable by medication and who are therefore candidates for therapeutic surgery but whose EEGs fail to lateralize the most involved hemisphere. In these patients bilateral epileptiform spiking makes lateralization impossible or at least uncertain. The research under this current grant has therefore focussed on an attempt to enhance the EEG findings, the technique used being the adoption of the anti-convulsant diazepam shown in this study to evoke a different reaction from epileptogenic tissue from that given by normal brain. These changes require the fine analysis available only by computer analysis, changes that are quantified and avoid errors introduced by visual inspection of the EEG recordings. The success of this method for enhancing the EEG findings in a group of these difficult cases has been reported in a paper currently in press. BIBLIOGRAHPIC REFERENCES: Brazier, M.A.B., Crandall, P.H. and Brown, J. W. Long term follow-up of EEG changes following therapeutic surgery in epilepsy. Electroenceph. clin. Neurophysiol., 38: 495-506, 1975. Brazier, M.A.B. Cerebral localization: the search for functional representation in the cortex. Acta Neurobiol. Exp. 35: 557-563, 1975.